Crinone 8% vaginal progesterone gel results in lower embryonic implantation efficiency after in vitro fertilization-embryo transfer

Objective: To evaluate the outcome of IVF-ET after the use of Crinone 8% (Wyeth-Ayerst Laboratories, Inc., Philadelphia, PA) vaginal progesterone gel and to compare these results with those seen in our program with the use of IM progesterone-in-oil. Design: Retrospective cohort study. Setting: A tertiary referral reproductive medicine unit. Patient(s): Patients <40 years of age undergoing IVF-ET cycles. Intervention(s): Patients were treated with either Crinone 8% vaginal progesterone gel (90 mg) administered daily or IM progesterone-in-oil (50 mg) administered daily. Main Outcome Measure(s): Biochemical pregnancy rate, implantation rate, and clinical and ongoing pregnancy rates. Result(s): The use of Crinone 8% vaginal progesterone gel was associated with a lower implantation rate (16.6% versus 26.2%; odds ratio [OR] = 0.56; 95% confidence interval [CI], 0.35-0.89) compared with the use of IM progesterone-in-oil. Biochemical pregnancies were more common after the use of Crinone 8% vaginal progesterone gel as defined by either biochemical pregnancies per transfer (15.9% versus 5.7%; OR = 3.11; 95% CI, 1.17-8.32) or biochemical pregnancies as a proportion of positive serum hCG titers (29.2% versus 9.8%; OR = 3.80; 95% CI, 1.33-10.86). Clinical pregnancy rates also were lower with the use of Crinone 8% vaginal progesterone gel (36.4% versus 52.9%; OR = 0.51; 95% CI, 0.26-0.99). Conclusion(s): Implantation efficiency is reduced, as demonstrated by lower embryonic implantation rates and higher biochemical pregnancy rates, when Crinone 8% vaginal progesterone gel rather than IM progesterone-in-oil is used for luteal phase support after IVF-ET.